Screws are used in various settings for attachment to vertebral members. The screws may be used to attach together the vertebral member, or may be used to attach a support device, such as a vertebral rod. In one specific embodiment, screws are attached to the pedicle. One issue with previous screws is that the interface between the thread and the bone experiences stresses immediately following installation. This is especially seen in the thread-to-cancellous bone interface. The thread interface may tend to slip or move after installation, thus inhibiting bone adhesion and bone growth.
Bone growth materials have been used to promote bone growth. One application is the use of bone growth materials to facilitate attachment of a vertebral member to an intervertebral device, such as an intervertebral spacer. The bone growth material is delivered with the spacer and positioned in a manner to promote growth with the vertebral member. However, screws have been unable to adequately carry the bone growth material to the desired location within the vertebral member.